tonyjer wrote:169/279/38/13458/345/1345/458/257/4678...Am I right in identifying 2679?

Yes, 2679 can go only into columns 1,2,7 and 8 (of this row). So they are restricted to these numbers and you can eliminate 1 from column 1 (leaving 69), 5 from column 8 (leaving 27) and 48 from column 9 (leaving 67).